Many reports show that KRAS mutations are highly specific negative predictors of response to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) monotherapy in advanced non-small-cell lung cancer (NSCLC) and similarity to anti-EGFR monoclonal antibodies alone or in combination with chemotherapy in metastatic colorectal cancer (mCRC)[15-18]. Here, KRAS is linked to metastatic colorectal cancer.